Metadata

Abstract

Land surface albedo is a critical variable needed in
land surface modeling. The conventional methods for estimating
broadband albedos rely on a series of steps in the processing chain,
including atmospheric correction, surface angular modeling, and
narrowband-to-broadband albedo conversions. Unfortunately,
errors associated with each procedure may be accumulated and
significantly impact the accuracy of the final albedo products.
In an earlier study, we developed a new direct procedure that
links the top-of-atmosphere spectral albedos with land surface
broadband albedos without performing atmospheric correction
and other processes. In this paper, this method is further improved
in several aspects and implemented using actual Moderate Resolution
Imaging Spectroradiometer (MODIS) imagery. Several
case studies indicated that this new method can predict land
surface broadband albedos very accurately and eliminate aerosol
effects effectively. It is very promising for global applications and
is particularly suitable for nonvegetated land surfaces. Note that
a Lambertian surface has been assumed in the radiative transfer
simulation in this paper as a first-order approximation; this
assumption can be easily removed as long as a global bidirectional
reflectance distribution function climatology is available,